Intersubject Spatial Pattern Correlations During Movie Viewing Are Stimulus-Driven and Nonuniform Across the Cortex

Area of Science:

• Neuroscience
• Cognitive Science
• Neuroimaging

Background:

• Predicting brain activity requires understanding shared responses to experiences.
• Multivoxel pattern analysis (MVPA) investigates information encoding but hasn't explored local, stimulus-driven cortical activity during naturalistic stimulation.
• Characterizing basic shared responses across subjects is crucial for understanding brain function in health and disease.

Purpose of the Study:

• To examine local, stimulus-driven patterns of cortical activity during naturalistic stimulation.
• To characterize the most basic degree of shared response between subjects using minimal interpolation.
• To investigate shared spatial patterns in functional magnetic resonance imaging (fMRI) responses across a large group.

Main Methods:

• Utilized an unbiased analytic approach.
• Employed rich, naturalistic, and nonsemantic stimulation.
• Analyzed functional magnetic resonance imaging (fMRI) data with minimal interpolation, excluding functional alignment.

Main Results:

• Meso-scale spatial patterns were shared nonuniformly across the visual cortex.
• Shared spatial patterns were distinct from the shared temporal response.
• Shared spatial patterns were stimulus-driven, modulated by pattern size, and sensitive to 3D vs. 2D stimulus differences.

Conclusions:

• Even at a meso-scale, common spatial structures are shared across individuals with anatomical alignment alone.
• The strength of shared spatial similarity varies across the cortex, indicating innate organization and plasticity.
• These findings suggest that some cortical structures are inherently organized, while others are shaped by experience and learning.